Variable Angle Locking Rotation Correction Plate

ABSTRACT

A bone plate sized and shaped for fixation to one of a phalangeal and metacarpal bone includes a head extending from a first end to a second end and having an elongated curved plate hole extending therethrough along a curved path from a first end to a second end, a plate hole axis of the elongated curved plate hole extending orthogonally from a top surface to a bone contacting surface of the bone plate and a shaft extending from the head, the shaft including an elongated shaft plate hole extending therethrough and elongated in a direction extending orthogonal to a central longitudinal axis of the bone plate, a plate hole axis of the elongated shaft plate hole extending orthogonally from the top surface to the bone contacting surface.

PRIORITY CLAIM

The present application is a Continuation Application of U.S. patentapplication Ser. No. 14/320,525 filed on Jun. 30, 2014. The entiredisclosure of this patent(s)/application(s) expressly incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention generally relates to bone plates for the fixationof fractures of the hand and methods of coupling these plates to bone.

BACKGROUND

Many current systems and methods for the fixation of fractures,especially fractures in the hand, are limited in the placement andorientation of plates over the bone. For example, a surgeon or otheruser may be required to select a final placement position of the boneplate prior to beginning a bone reduction procedure. Such plates mayprevent the surgeon from selecting the most optimal implantationlocation for the bone plate. Furthermore, such plates may prevent thefixation of a fractured or otherwise damaged bone in a manner to fullycorrect the alignment of one or more bone fragments. Rather, suchfragments must be brought as close to a final configuration as possibleprior to the placement of the bone plate thereover, which may result insubsequent misalignment as the bone plate is being secured to the bone.Rotational misalignments are especially problematic due to crossing andscissoring of the digits when a full flexion of the fingers (e.g.,making a fist) is attempted. Even minor rotational errors in the fingersmay have to be surgically corrected after a fracture has healed.Furthermore, this method of insertion may also compromise adjacent softtissue.

SUMMARY OF THE INVENTION

The present invention is directed to A bone plate sized and shaped forfixation to one of a phalangeal and metacarpal bone, comprising a headextending from a first end to a second end and having an elongatedcurved plate hole extending therethrough along a curved path from afirst end to a second end, a plate hole axis of the elongated curvedplate hole extending orthogonally from a top surface to a bonecontacting surface of the bone plate and a shaft extending from thehead, the shaft including an elongated shaft plate hole extendingtherethrough and elongated in a direction extending orthogonal to acentral longitudinal axis of the bone plate, a plate hole axis of theelongated shaft plate hole extending orthogonally from the top surfaceto the bone contacting surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Several embodiments of the invention will be described in the followingby way of example and with reference to the accompanying drawings inwhich:

FIG. 1 shows a top view of a bone fixation plate according to a firstexemplary embodiment of the invention;

FIG. 2 shows a bottom view of the bone fixation plate of FIG. 1;

FIG. 3 shows a perspective view of the bone fixation plate of FIG. 1;and

FIG. 4 shows a side view of the bone fixation plate of FIG. 1.

DETAILED DESCRIPTION

The exemplary embodiments may be further understood with reference tothe following description and the appended drawings, wherein likeelements are referred to with the same reference numerals. The exemplaryembodiments relate to apparatus and methods for the treatment offractures and, in particular, to devices for fixing fractures of themetacarpals and phalanges. Exemplary embodiments describe a bonefixation plate having a head at a first end with an elongated shaftextending therefrom to a second end. The head of the exemplary boneplate includes first and second variable angle fixation holes along afirst side thereof. The head also includes an elongated curved holeextending along a second side thereof. The elongated curved hole permitsrotation and angulation of the bone plate about a cortex screw insertedtherethrough as will be described in more detail below. The shaftincludes third, fourth and fifth plate holes staggered about a centrallongitudinal axis of the bone plate and an elongated plate holeextending along an axis orthogonal to the central longitudinal axis. Aswill be described in greater detail later on, the elongated hole furtheraids in optimally positioning the plate over a target portion of thebone. The shaft further may comprise sixth and seventh variable anglelocking holes at a second end thereof. The sixth and seventh holes arealigned with the central longitudinal axis. A bone contacting surface ofthe head has a curvature selected to conform to a curvature of a dorsalsurface of a bone to ensure flush seating of the plate thereover. Aswill be described in greater detail later on, the exemplary curved andelongated plate holes permit the adjustment of rotation and angulationof the bone plate prior to a final fixation of the bone plate to thebone.

As shown in FIGS. 1-4, an exemplary bone plate 100 has a head 104 at afirst end 102 thereof and a shaft 108 extending therefrom generallyalong a central longitudinal axis 110 to a second end 106. The head 104includes first and second variable angle plate holes 112, 114 extendingtherethrough from a bone contacting surface 116 to an upper surface 118,the first and second plate holes 112, 114 being open to one another atan opening 111. Trajectories for plate hole axes 113, 115 of the firstand second plate holes 112, 114 are selected to capture common fracturepatterns while avoiding the articular surface of the bone and minimizinginterference with adjacent collateral ligaments. As shown in FIG. 4, theplate hole axes 113, 115 may be generally orthogonal to the top surface118 while the variable angle feature of the plate holes 112, 114 permitsa surgeon to vary an angle at which screws are inserted through theseholes (relative to the hole axes) to optimize these trajectories to suitthe anatomy of a particular patient.

The head 104 further comprises an elongated curved plate hole 122extending from a first end 124 to a second end 126 along a curvedarc-shaped axis 123. A length of the plate hole 122 between the firstand second ends 124, 126 is greater than a diameter of the first andsecond plate holes 112, 114. A width of the plate hole 122 is equivalentto a diameter of the first and second plate holes 112, 114. A length ofthe plate hole 122 may be equivalent to or slightly longer than a lengthof a combination of the first and second plate holes 112, 114. The firstand second plate holes 112, 114 and the curved plate hole 122 may besized, shaped and positioned along the head 104 to maximize the amountof area for screw placement while minimizing the foot print of the head104 and maintaining strength of the plate 100.

A radius of curvature of the plate hole 122 may be, for example, 3.75 mmor 5.0 mm, although other values are depicted within the scope of theinvention. A center from which the radius of curvature of the plate hole122 may be measured may be located through, for example, the first platehole 112. The curved plate hole 122 follows a banana-like curvature,curving toward the central longitudinal axis 110 so that the first end124 is further from the axis 110 than is the second end 126. Theexemplary curvature of the elongated curved plate hole 122 permits thebone plate to slide along the curve about a bone screw insertedtherethrough. Specifically, the bone screw (not shown) may be insertedinto the elongated curved plate hole 122 at a position selected tocapture one or more bone fragments. The bone screw (not shown) may beinserted through the bone plate 100 and bone (not shown) to a firstdepth permitting the bone plate 100 to be movable about the bone screw.Subsequent sliding of the bone plate 100 along the axis 123 moves thebone plate 100 along a curved path corresponding to the path 123 as thebone plate 100 is moved in first and second directions along the centrallongitudinal axis 110. Furthermore, a surgeon or other user may rotatethe bone plate 100 about the bone screw (not shown) received in theelongated plate hole 122 to achieve a desired orientation over the bone,as will be described in greater detail with respect to the exemplarymethod below. As phalange and metacarpal fractures typically result in abreakage of the “head” or “condyle” to a smaller fragment, the curvedplate hole 122 located in the head 104 permits the surgeon or other userto affix the head 104 of the plate 100 to that smaller fragment first,and then would have the ability to rotate the plate to fit the shaft.

An outer surface of the head 104 substantially follows a position of thefirst, second and elongated plate holes 112, 114, 122. Specifically, afirst side wall 128 of the head 104 follows a curved path correspondingto a curvature of the elongated plate hole 122. A second side wall 130of the head 104 is also curved to conform to the shape of the first andsecond plate holes 112, 114, the size and curvature of the second wall130 being formed so that a minimum clearance is formed about the firstand second plate hole 112, 114. A first notch 132 is formed on thesecond side wall 130 of the head 104 and has a substantially roundedshape. The first notch 132 is formed as a cutout extending into thesecond side wall 130 and has a shape corresponding to an arc of acircle. In another embodiment, the first notch 132 may have anon-circular shape (e.g., oblong, etc.) without deviating from the scopeof the invention. The first end 102 of the bone plate 100 also comprisesa second notch 134 positioned between the first and elongated plateholes 112, 122, the second notch 134 also having a substantially roundedshape. In one embodiment, the second notch 134 has a radius of curvatureof 1.5 mm or 2.0 mm. However, this radius of curvature is exemplary onlyand other values may be used without deviating from the scope of theinvention. The second notch 134 is centered with respect to the centrallongitudinal axis 110 of the bone plate. In another embodiment, thesecond notch 134 may have a non-circular shape (e.g., oblong, etc.)without deviating from the scope of the invention. The first and secondnotches 132, 134 also effectively reduce an outer profile of the boneplate 100 without compromising the structural integrity thereof.

The bone-contacting surface 116 of the bone plate 100 is curved toconform to the curvature of a target dorsal surface of a metacarpal orphalangeal bone. In one embodiment, the bone-contacting surface 116 ofthe head 104 includes curvatures of varying radii. A predeterminedlength of the head 104 at the first corner 122 may be curved downwardtoward the bone in a direction toward a palmar surface of the bone in animplanted configuration. This downward curvature aids in reduction ofthe fracture.

A reduced diameter neck 136 separates the head 104 from the shaft 108.The shaft 108 extends distally from the neck 136 to the distal end 106and includes third, fourth, fifth, sixth and seventh variable angleplate holes 138, 140, 142, 144, 146. In one embodiment, trajectories139, 141, 143, 145, 147 of the third, fourth, fifth, sixth and seventhplace holes 138, 140, 142, 144, 146 are orthogonal to a plane housingthe bone plate 100 while the variable angle features thereof permit asurgeon to vary the angles at which screws are inserted therethrough tooptimize these trajectories to suit the anatomy of a particular patient.Thus, the trajectories 139, 141, 143, 145, 147 may assume any pathselected to lockingly engage the bone without extending through anopposing cortical surface thereof. The third, fourth and fifth plateholes 138, 140, 142 are staggered about the central longitudinal axis110 so that central axes 139, 141, 143 thereof are offset relative tothe axis 110. The staggered shaft portion of the plate 100 increasesplate strength and allows for distribution of bone screws over a largersurface area of the bone to capture fracture fragments in a comminutedshaft, as those skilled in the art will understand. Specifically, thethird and fifth plate holes 138, 142 are offset in a first directiontoward a first side wall 148 of the shaft 108. Specifically, the thirdand fifth plate holes 138, 142 extend away from the axis 110 in thefirst direction by a distance greater than any other portion of theshaft 108. In a preferred embodiment, the central axis 139 of the thirdplate hole 138 is separated from the axis 110 by a distance D₁ and thecentral axis 143 of the fifth plate hole 142 is separated from the axis110 by a distance D₂, wherein D₁ is greater than D₂. The fourth platehole 140 is offset in a second direction toward a second side wall 150of the shaft 108 so that a distance D₃ is formed between a central axis141 of the fourth plate hole 140 and the axis 110. The distances D₂ andD₃ may be substantially equivalent to one another. The central axes 141,143 of the fourth and fifth plates holes 140, 142, respectively, may becloser to the axis 110 than the central axis 139 of the third plate hole138 since the phalanges and metacarpals become thinner towards a centralportion thereof. It will be understood by those of skill in the art,however, that D₁ is not required to be greater than D₂ and D₃, so longas the third, fourth and fifth holes 138, 140, 142 are positionedthrough the plate 100 so that, when the plate 100 is positioned along abone, the third, fourth and fifth holes 138, 140, 142 extend along aportion of the bone. It will also be understood by those of skill in theart that although the exemplary embodiment shows the third and fifthholes 138, 142 as offset from the axis 110 in the first directiontowards the first side wall 148 and the fourth plate hole 140 is offsetfrom the axis 110 in the second direction toward the second side wall150, a direction in which the third, fourth and fifth holes 138, 140,142 are offset may also be reversed. In particular, the third and fifthholes 138, 142 may be offset in the second direction while the fourthhole 140 may be offset in the first direction.

The shaft 108 also includes an elongated hole 152 elongated in adirection orthogonal to the longitudinal axis 110. The elongated hole152 is centered about the central longitudinal axis 110, a trajectory153 thereof extending orthogonally from the bone contacting surface 116to the top surface 118. An axial length of the elongated hole 130 is atleast larger than a diameter of the first through seventh plate holes112, 114, 138, 140, 142, 144, 146 while a width of the elongated hole152 may be equivalent to the diameter of first through seventh plateholes 112, 114, 138, 140, 142, 144, 146. In a preferred embodiment, thefirst through seventh plate holes 112, 114, 138, 140, 142, 144, 146 are1.5 mm variable angle holes. However, in another embodiment, one or moreof the first through seventh plate holes 112, 114, 138, 140, 142, 144,146 may be formed as standard locking holes having a diameter of 2.0 mm.Still further, it is noted that any other diameter of the holes may beused without deviating from the scope of the invention to conform to therequirements of a particular procedure. As will be described in greaterdetail below with respect to the exemplary method, the elongated hole130 permits a surgeon or other user to slide the bone plate 100 over thebone within a predetermined range (i.e., corresponding to a length ofthe elongated hole 152) prior to locking the bone plate 100 in place. Inone embodiment, the elongated hole 130 may allow for a movement of thebone plate along an axis 154 while also permitting rotation of the boneplate 100 therearound. Specifically, a surgeon or other user may inserta first bone screw into one of the elongated holes 122, 152 to affect aposition of the bone plate 100 over the bone, as will also be describedin greater detail later. The exemplary elongated plate hole 152 extendsorthogonally through the bone plate from the upper surface 118 to thebone contacting surface 116. The elongated holes 122, 152 bypass theneed for a guidewire to position the bone plate 100 over the bone.Rather, since the bone plate 100 is adjustable relative to a bone screwinserted through the elongated hole 122, 152, a surgeon or other usermay use the elongated holes 122, 152 as a guide when positioning thebone plate 100 over the bone.

The sixth and seventh holes 144, 146 are axially aligned andsymmetrically positioned relative to the central longitudinal axis 110.

The bone-contacting surface 116 of the shaft 108 is curved along thelongitudinal axis 110 to conform to the substantially cylindrical shapeof the target portion of the bone over which the shaft 108 will beseated. In one embodiment, the length of the shaft 108 may include asingle uniform curvature. In another embodiment, the bone contactingsurface 116 of the shaft 108 may include a plurality of curves selectedto ensure that the shaft 108 is seated flush over the bone.

The shaft 108 also includes a plurality of first webbed portions 158extending along the first side wall 148 between each of the holes 138,142, 144, 146 and a plurality of second webbed portions 160 extendingalong the second side wall 150 between each of the holes 114, 140, 152,144, 146. The first and second webbed portions 158, 160 are formed asnotches extending into the width of the bone plate 100 reducing aprofile thereof while maintaining the structural integrity of the boneplate 100. The first and second webbed portions 158, 160 as well as thefirst and second notches 132, 134 are sized to maintain a minimumdesired clearance remains around the boundary of each of the plate holesof the bone plate 100. An outer periphery of the bone plate 100 mayinclude a rounded taper to further reduce the profile as would beunderstood by those skilled in the art.

The bone-contacting surface 116 of the bone plate further comprises aplurality of undercuts 162, 164, 166, 168, 170, 172 positioned betweenplate holes to permit bone ingrowth while also imparting additionalflexibility to the bone plate 100 to permit a surgeon to further bendthe bone plate 100 to a desired curvature to more closely match theanatomy of a patient's bone and promote healthier bone ingrowth. Theundercuts 162, 164, 166, 168, 170, 172 are formed as cutouts extendinginto the bone plate 100 from the bone-contacting surface 116 by a depthsmaller than a thickness of the bone plate 100. In a preferredembodiment, a shape of the cutouts is a half-cylindrical segment,although other shapes (e.g., rectangular, etc.) may be used withoutdeviating from the scope of the invention. First, second and thirdundercuts 162, 164, 166 are angled with respect to the axis 110 inaccordance with a position of the third, fourth and fifth plate holes138, 140, 142. Specifically, the first undercut 162 encloses an angle of105° relative to the axis 110. The second undercut 164 encloses an angleof 60° relative to the axis 110. The third undercut 166 encloses anangle of 120° relative to the axis 110. Fourth, fifth and sixthundercuts 168, 170, 172 extend orthogonally to the axis 110.

The exemplary bone plate 100 is configured for use in indirect reductiontechniques for crushes, multi-fragmented and/or periarticular fracturesof the metacarpals and phalanges. In accordance with an exemplary methodaccording to the invention, the bone plate 100 is positioned over atarget dorsal surface of a bone in a target orientation so that theelongated curved plate hole 122 is positioned adjacent a far side of afracture near a section of intact bone. The surgeon or other userapproximates the desired position of the bone plate 100 over the bone. Afirst cortex screw (not shown) is then inserted through the elongatedcurved hole 122 and into the bone to a first depth sufficient to holdthe bone plate 100 over the bone while still permitting movement of thebone plate 100 relative to the bone The bone plate 100 is then slidalong the axis 123 about the first cortex screw (not shown) received inthe hole 122 until a desired position has been reached. The first cortexscrew (not shown) may be tightened and loosened a plurality of timesduring this repositioning. A second cortex screw (not shown) is theninserted into the elongated hole 152 to the first depth sufficient tohold the bone plate 100 over the bone while still permitting movement ofthe bone plate 100 relative to the bone. The bone plate 100 is thenrepositioned along the axis 154 to a desired final configuration. Thefirst and second cortex screw (not shown) may be tightened and looseneda plurality of times during the above repositioning. The exemplary boneplate 100 according to the invention allows for an adjustment ofrotation and angulation of the bone plate 100 prior to a permanentfixation thereof over the bone. Once the target position has beenreached, additional screws (not shown) may be inserted into any of theremaining plate holes 112, 114, 138, 140, 142, 144, 146. The exemplarysystem and method according to the invention bypasses the need forpre-drilling holes in the bone. Rather, once the target position hasbeen achieved, bore holes are drilled through any of the plate holes112, 114, 138, 140, 142, 144, 146 and into the bone at a desired angleselected to conform to the requirements of the particular bone. Incontrast, present bone fixation systems require the insertion of aguidewire into the bone prior to the placement of the bone plate overthe bone, thus requiring that a final position of the bone plate 100 beselected prior to the placement of the bone plate over the bone. Thismethod may lead to reduced accuracy in placement, especially in thefixation of phalangeal bones where even the smallest deviation, (e.g.,in millimeters) from a correct position may lead to less than optimumfixation. The exemplary bone plate 100, on the other hand, permitsadjustment of the position of the bone plate 100 even after the boneplate 100 has been initially secured to the bone, thereby ensuring thatthe final position of the bone plate 100 captures all fragments of thebone while avoiding interference with ligaments, tendons or othertissue.

It will be appreciated by those skilled in the art that variousmodifications and alterations of the disclosed embodiments may be madewithout departing from the broad scope of the invention. Some of thesehave been discussed above and others will be apparent to those skilledin the art.

1-20. (canceled)
 21. A method for bone fixation, comprising: positioninga bone plate over a dorsal surface of a one of a phalangeal andmetacarpal bone, the bone plate extending from a first end having a headto a second end having a shaft; inserting a first fixation element intoan elongated curved plate hole extending through the head by a firstdepth, wherein the elongated curved plate hole extends along a curvedpath from a first end to a second end, a plate hole axis of theelongated curved plate hole extending orthogonally from a top surface toa bone contacting surface of the bone plate; sliding the bone plate overthe bone within a first range of motion limited by a length of theelongated curved plate hole to a desired location over the bone;inserting a second fixation element into an elongated shaft plate holeextending through the shaft and elongated in a direction extendingorthogonal to a central longitudinal axis of the bone plate; sliding thebone plate over the bone within a second range of motion limited by alength of the elongated shaft plate hole to a desired location over thebone; and inserting a third fixation element into the second fixationelement hole to lock the bone plate over the bone.
 22. The method ofclaim 21, further comprising: rotating the bone plate about the firstfixation element to the desired location prior to insertion of secondand third fixation elements thereinto.
 23. The method of claim 21,further comprising: tightening the first fixation element into theelongated curved plate hole to a second depth greater than the firstdepth to lock the bone plate to the bone.
 24. The method of claim 21,further comprising: tightening the second fixation element.
 25. Themethod of claim 21, wherein the elongated curved plate hole ispositioned on a first side of the central longitudinal axis.
 26. Themethod of claim 24, wherein the head includes first and second variableangle plate holes extending therethrough on a second side of the centrallongitudinal axis.
 27. The method of claim 21, wherein the head includesa first notch on the first end between the elongated curved plate holeand the first variable angle plate hole, the first notch formed as anindentation on an outer wall of the bone plate.
 28. The method of claim21, wherein the shaft further includes third, fourth and fifth variableangle plate holes extending therethrough and positioned between the headand the elongated shaft plate hole.
 29. The method of claim 21, whereinthe elongated shaft plate hole is centered about the centrallongitudinal axis.
 30. The method of claim 1, wherein the shaft includesa plurality of shaft notches formed in first and second side wallsthereof, the shaft notches defining reduced width regions of the shaft.31. A method for fixation of one of a phalangeal and metacarpal bone,comprising: positioning a bone plate over a dorsal surface of the bonein a target orientation so that an elongated curved plate hole ispositioned adjacent to a fracture near a section of intact bone, thebone plate extending from a first end having a head to a second endhaving a shaft, wherein the bone has not been pre-drilled; inserting afirst fixation element into the elongated curved plate hole extendingthrough the head by a first depth, the elongated curved plate holeextending along a curved path from a first end to a second end, a platehole axis of the elongated curved plate hole extending orthogonally froma top surface to a bone contacting surface of the bone plate; slidingthe bone plate over the bone within a first range of motion limited by alength of the elongated curved plate hole to desired location over thebone; bending the bone plate to a desired curvature to more closelymatch the anatomy of the bone; inserting a second fixation element intoan elongated shaft plate hole extending through the bone plate andelongated in a direction extending orthogonal to a central longitudinalaxis of the bone plate; and sliding the bone plate over the bone withina second range of motion limited by a length of the elongated plate holeto a desired location over the bone.
 32. The method of claim 31, furthercomprising: rotating the bone plate about the first fixation element tothe desired location prior to insertion of second and third fixationelements thereinto.
 33. The method of claim 31, further comprising:inserting a third fixation element into the second fixation element holeto lock the bone plate over the bone.
 34. The method of claim 31,further comprising: tightening the first fixation elements into theelongated curved plate hole.
 35. The method of claim 31, wherein theelongated curved plate hole is positioned on a first side of the centrallongitudinal axis.
 36. The method of claim 35, wherein the head includesfirst and second variable angle plate holes extending therethrough on asecond side of the central longitudinal axis.
 37. The method of claim31, wherein the head includes a first notch on the first end between theelongated curved plate hole and the first variable angle plate hole, thefirst notch formed as an indentation on an outer wall of the bone plate.38. The method of claim 31, wherein the shaft further includes third,fourth and fifth variable angle plate holes extending therethrough andpositioned between the head and the elongated shaft plate hole.
 39. Themethod of claim 31, wherein the elongated shaft plate hole is centeredabout the central longitudinal axis.
 40. The method of claim 31, whereinthe shaft includes a plurality of shaft notches formed in first andsecond side walls thereof, the shaft notches defining reduced widthregions of the shaft.